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Posted to users@activemq.apache.org by "Suchitha Koneru (sukoneru)" <su...@cisco.com> on 2007/02/07 20:38:17 UTC
active mq (size of the internal data structure and expiration of messages)
Hello Active Mq Users ,
I am using Publish/subscribe model for transfer of
messages with durable subscriptions. I suppose that active mq
internally stores messages using queue or a similar data structure.
I was just wondering about the size of this queue maintained internally
by Active MQ. Does it overflow ? How will we know, what it's capacity
is ?
Any insight in regard to this ?
Also , the messages place in this internal queue will be discarded ,
once they expire ? What is the time frame , within which they have to
be consumed ? is there a way to determine this?
thanks,
Suchitha
Re: active mq (size of the internal data structure and expiration of messages)
Posted by Rob Davies <ra...@gmail.com>.
On 7 Feb 2007, at 19:38, Suchitha Koneru ((sukoneru)) wrote:
> Hello Active Mq Users ,
> I am using Publish/subscribe model for
> transfer of
> messages with durable subscriptions. I suppose that active mq
> internally stores messages using queue or a similar data structure.
yes it does. For Durable Subscribers, there is one queue for the
messages, and for each subscriber a queue of references, one
reference, per message for each subscriber. When there are no more
interested subscribers in the message, it will be removed from the
message queue.
>
> I was just wondering about the size of this queue maintained
> internally
> by Active MQ. Does it overflow ? How will we know, what it's capacity
> is ?
> Any insight in regard to this ?
We support a lot of different storage options, and although we expose
the depth (cardinality) of the queue, as yet, we do not provide a
generic mechansim for imposing limits on the durable messages.
> Also , the messages place in this internal queue will be
> discarded ,
> once they expire ? What is the time frame , within which they have to
> be consumed ? is there a way to determine this?
Messages are generally discarded when they expire. Some storage
options only do this when fetching the messages (check to see if the
message should be expired) - others do it periodically (this will
become the norm for all message stores).
cheers,
Rob Davies
http://rajdavies.blogspot.com/
>
> thanks,
> Suchitha